Beer from rainwater, any issues?

My water supply is from rainwater, it is very soft. What effect will this have on my beer brewing? Should I care about this?

thanks,
Bill P

If you're doing extract kits, you're probably fine, but as you use liquid yeast and move to all-grain, it becomes more important.
Yeast does indeed want some particular mineral characteristics, but these are usually provided in dry yeast. There are some good primers about this as stickies in the water chem section, but in general:

- Calcium, magnesium, and zinc are all very important to yeast function. If you're using dry yeast the yeast will typically be enriched with that already so it's less of a concern, but liquid yeast would especially benefit. - Similarly, if you're doing extract the presence of particular ions and pH is less of a priority than it is in all-grain or mashing.

Based on that, I'd say there aren't any "fires to put out." If you are doing all-grain, though, you should get familiar with the ions and pH necessary for our favorite malty enzymes.

My favorites were the Munich or Wurzburg wheat beers. I wonder what kind of water they have ....

Hmmm ... rainwater, grain alcohol ....

Munich historically had harder water (hence its development of darker beers, which would help lower the pH).
...but try it with the soft water first, because I think you'll find it delicious as is, most likely.

Here's the data from BeerSmith for Munich, if you want to try to recreate it:
Name: Munich, Germany
PH: 8.00

Ions: (in ppm)
Calcium: 75.00
Magnesium: 20.00
Sodium: 10.00
Sulfate: 10.00
Chloride: 2.00
Bicarbonate: 200.00